The present invention is directed to a nail retaining strip or nail strip with nails arranged in parallel relation and held together by severable connecting means. Such a nail strip is used in a fastening element driving tool using a piston for driving the nails out of a muzzle bore in the tool. The muzzle part of the tool has a passage for inserting the nails one at a time into the bore. On the opposite side of the bore from the passage a recess extending radially outwardly and in the axial direction is arranged to receive a portion of the connecting means.
Nail strips are used in piston type driving tools and have considerable advantages over feeding devices for supplying individual nails, not connected together, into the tools. The use of nail strips permits an automatic feed and rapid nail placement cycles along with avoidance of the loss of nails.
In DE-OS No. 28 10 069 a known nail strip is disclosed where the nails formed of a head and a shank are formed in one piece out of metal plates with the heads of adjacent nails held together by severable connecting means. The connecting means are in the form of narrow metal strips projecting from the nail heads and the strips are severed in the center between the heads when the piston drives the nail out of the tool. The individual nails are driven by the piston from the muzzle bore into a receiving material.
It is the purpose of the connecting means not only to hold the nails together in a strip form but also to insure the parallel alignment of the nail shanks relative to one another. Such parallel alignment of the nail shanks is difficult to maintain, because it is easy for the connecting means to become bent. Moreover, a complete utilization of the nail strip is impossible since at least the last nail to be driven from the strip arrives in the muzzle bore without any defined guided position. As a result, the last few nails in the strip cannot be used since the remaining portion of the strip cannot provide adequate guidance in the radial passage into the muzzle bore of the driving tool.
When an adjacent nail has been driven from the known strip, a half portion of the connecting means remains and projects from the nail positioned within the muzzle bore. To afford adequate axial support during the severing process the half portion of the connecting means extends into a receiving opening formed in the wall of the muzzle bore opposite the passage through which the nail is introduced into the bore.